Tree Management Report - Planning Commission · Coral Tree) located at 202 Tynte Street, North...

Tree Management Report

Site: 202 Tynte Street, North Adelaide

Date: Tuesday, 13 February 2018

ATS4879-202TynStTMR

Arborman Tree Solutions Pty Ltd – Professionals in Arboriculture Phone: (08) 8240 5555

23 Aberdeen Street ATS4879-202TYNSTTMR – TUESDAY, 13 FEBRUARY 2018 Fax: (08) 8240 4525

Port Adelaide SA 5015 Email: [email protected]

Contents

Brief ..................................................................................................................................................................1

Documents and Information Provided .............................................................................................................1

Executive Summary .........................................................................................................................................1

Assessment ......................................................................................................................................................2

Observations ..............................................................................................................................................2

Development Plan Principles of Development Control ..............................................................................3

Photographs ...............................................................................................................................................4

Discussion ........................................................................................................................................................7

Recommendation .............................................................................................................................................8

Glossary ...........................................................................................................................................................9

References .......................................................................................................................................................9

Appendix A – Tree Location

Appendix B – Tree Protection Zone

Report Reference Number: ATS4879-202TynStTMR

Report prepared for

John Culshaw

Author

Gary Moran, Consulting Arborist, Arborman Tree Solutions Pty Ltd

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Brief Arborman Tree Solutions was engaged to conduct an assessment of the Erythrina x sykesii (Coral Tree) located at 202 Tynte Street, North Adelaide and provide information in relation to the following points: -

➢ Assess the health and structure of the subject tree. ➢ Assess the tree for removal against the Development Act 1993 and the Adelaide City Council

Development Plan relating to Significant Trees. ➢ Calculate the Tree Protection Zone (TPZ) and in accordance with Australian Standard

AS4970-2009 Protection of trees on development sites. ➢ Provide any additional relevant information.

Documents and Information Provided ➢ Plan 15.225.DA.02B ➢ Plan 15.225.DA.03

Executive Summary Arborman Tree Solutions was engaged to assess Significant Tree Number 603 for removal as it is in direct conflict with a large scale redevelopment at 202 Tynte Street, North Adelaide. This assessment found the tree to be in poor structural condition with a substantial history of branch and stem failure. Additionally, the tree’s poor condition and inconspicuous location indicate its contribution to the area is limited. Reasonable structural remediation options such as pruning, support cables and bracing were determined to be ineffective and/or unwarranted. This assessment has determined the tree meets the criteria for removal of the City of Adelaide Development Plan due to its poor condition and its restriction of a large scale development.

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Assessment Observations

The subject tree is identified as Erythrina x sykesii (Coral Tree) and its status is as follows:-

Assessment Date: 13 February 2018

GPS Location: 34°54'21.65" S | 138°35'35.05" E

Height: 12 metres

Spread: 13 metres

Age: Mature

Useful Life Expectancy: Surpassed

Health: Fair

Structure: Poor

Circumference: 4.66 metres Legislative Control Status: TPZ: SRZ: Significant 12.48 metres 3.78 metres Retention Rating: Low – Tree with substantial structural defects without reasonable remedial management options

that is restricticting a large scale redevelopment.

➢ The location of the subject tree is highlighted on the attached aerial image (see Appendix A).

➢ The tree consists of three primary trunks. The western trunk has been lopped at 1.6 metres above ground level. The two remaining trunks support a bushy and irregular crown due to the aforementioned lopping and failed upper southern crown (see Photo 1).

➢ The root zone is almost entirely comprised of sealed surfaces and buildings.

➢ Health is fair as indicated by the reduced foliage density in the upper crown, however colour is normal. There is considerable epicormic growth present throughout the crown.

➢ Structure is poor as indicated by the included bark in the primary structure, large girdling roots, and substantial history of branch and stem failure (see Photo 2).

➢ The tree is located within the courtyard area and is largely restricted from public view from surrounding area (see Photo 3).

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Development Plan Principles of Development Control

The subject tree is listed as Significant Tree 603 within the Adelaide City Council Development Plan and is required to be assessed against the Principles of Development Control as follows:- a) The tree does not make an important contribution to the character or amenity of the local area.

The irregular shaped and bushy crown suggests the contribution is limited and not important.

b) The species is not indigenous to the local area.

c) The subject tree does not represent important habitat for indigenous fauna; as a non-native (exotic) that does not display suitable nesting hollows, this tree has limited habitat value.

d) The subject tree is not linked to a wildlife corridor or remnant area of native vegetation. The original vegetation in this area was cleared.

e) The subject tree is not important to the maintenance of biodiversity in the local environment; as a non-native (exotic) this tree has limited biodiversity value.

f) The tree does not form a notable visual element to the landscape of the local area; the tree is not considered to be remarkable, striking, eminent or worthy of particular note from public vantage points. The tree is not clearly visible from the Tynte Street frontage (see Photo 3).

In the case of removal, the following points are considered:-

A Significant Tree should not be removed other than where it can be demonstrated that one or more of the Principles of Development Control within the Adelaide City Council Development Plan apply.

a) The tree is not diseased; however, it has a short life expectancy due to the identified flaws within its structure that suggest a strong liklihood of ongoing branch and stem failures.

b) The tree does not currently represent an unacceptable risk to public or private safety as the site is unoccupied. The tree would likely become a material risk, however, if the area under the tree became frequently occupied by people.

c) The tree is not within a Bushfire Prone Area.

d) The tree is not causing or threatening to cause substantial damage to a substantial building or structure of value.

e) Other reasonable remedial treatments have been considered and determined to be ineffective. The health is fair; however, as the area under the tree is comprised almost entirely of sealed surfaces, reasonable remediation methods such as soil amelioration, mulch, and irrigation are not available.

f) Other reasonable development options do not appear to have been considered. Alternative designs have not been presented to me; however, as the tree is in poor condition without reasonable remediation options, they are unwarranted as the tree would be reccomended for removal irrespective of this or any development proposal.

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Photographs

Photo 1 - The failed southern crown

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Photo 2 - Included bark union and large girdling roots

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Photo 3 - The tree is inconspicuous from the Tynte Street frontage.

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Discussion Arborman Tree Solutions was engaged to assess Significant Tree Number 603 (Erythrina x sykesii-Coral Tree) located at 202 Tynte Street, North Adelaide for removal under the City of Adelaide Development Plan and the Development Act 1993. The tree is proposed for removal as it is in direct conflict with the proposed large scale redevelopment. This assessment found the tree to be in poor structural condition as indicated by the:

➢ Substantial history of branch and stem failure ➢ Large diameter girdling roots ➢ Included bark within the main union ➢ Lopping of the western stem The poor structural attributes listed above suggest the tree is likely to represent a material risk if the area under the tree became frequently used by people. The following structural remediation options were considered however were determined to be unwarranted and/or ineffective;

➢ Support cables and bracing are not warranted as the tree is not linked with considerable heritage, cultural, environmental or emotional values. The costs of their installation and frequent maintenance is unreasonable.

➢ The tree has limited pruning options consistent with Australian Standard AS4373-2007 Pruning of amenity trees to reduce the likelihood of ongoing branch and stem failures without further diminishing the already limited amenity.

The tree makes a limited however unimportant contribution to the character, amenity and environment of the area as;

➢ The species is not indigenous to the area. ➢ The previous lopping and branch failures has resulted in substantially diminished amenity. ➢ It is inconspicuous from the Tynte Street frontage. ➢ The species is not particularly consistent with the character of the area. ➢ No nesting sites or hollows were observed. This assessment recommends the removal of the tree as it meets the criteria for removal of the City of Adelaide Development Plan and the Development Act 1993. It should also be noted that the subject tree would be recommended for removal as part of best arboricultural management irrespective of this or any proposed redevelopment of the site.

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Recommendation 1. An application to remove Significant Tree 603 should be submitted to the Adelaide City

Council. 2. Written development approval from the Adelaide City Council must be obtained prior to

removing the tree. 3. The subject tree should be removed. Thank you for the opportunity to provide this report. Should you have any questions or require further information, please contact me and I will be happy to be of assistance. Yours sincerely

GARY MORAN Senior Consulting Arboriculturist Advanced Certificate in Arboriculture International Society of Arboriculture – Tree Risk Assessment

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Glossary Size: approximate height and width of tree in metres. Age: identification of the maturity of the subject tree. Useful Life Expectancy: expected number of the years that the subject specimen will remain alive and sound in its

current location and/or continues to achieve the relevant Principles of Development Control. Health: visual assessment of tree health. Structure: visual assessment of tree structure. Circumference: trunk circumference measured at one metre above ground level. This measurement is used to

determine the status of the tree in relation to the Development Act 1993. Diameter at Breast Height (DBH): trunk diameter measured at 1.4 metres above ground level used to determine the Tree

Protection Zone as described in Australian Standard AS4970-2009 Protection of trees on development sites.

Diameter at Root Buttress (DRB): trunk diameter measured just above the root buttress as described in Australian Standard

AS4970-2009 Protection of trees on development sites and is used to determine the Structural Root Zone.

Tree Protection Zone: area of root zone that should be protected to prevent substantial damage to the tree’s health. Structural Root Zone: calculated area within the tree’s root zone that is considered essential to maintain tree stability. Root Buttressing: area of root development as it joins to the trunk base. Bifurcation: a stem union supporting ascending stems and potentially containing included bark. Included Bark Union: a poorly formed stem or branch union where bark becomes trapped between the structural

fibres causing a weakness in the supporting structure. Epicormic Growth: regrowth developing from dormant buds located beneath the bark. Often developing as a result

of inappropriate pruning or tree related stress. Such growth can be associated with poor attachment and therefore an increased potential for failure.

Lopping: random cutting of branches or stems between branch unions usually resulting in epicormic

regrowth. Such pruning is not within Australian Standards AS4373-2007 Pruning of Amenity Trees.

References Australian Standard AS4373–2007 Pruning of amenity trees: Standards Australia.

Australian Standard AS4970–2009 Protection of trees on development sites: Standards Australia.

Matheny N. Clark J. 1998: Trees and Development a Technical Guide to Preservation of Trees During Land Development: International Society of Arboriculture, Champaign, Illinois, USA.

Matheny N. Clark J. 1994: Evaluation of Hazard Trees in Urban Areas: International Society of Arboriculture, Champaign, Illinois, USA. Julius A. Kocher W. Liefheit K. Lilly S. et al 2013: Tree Risk Assessment Qualification: International Society of Arboriculture, Champaign, Illinois, USA.




Appendix A – Tree Location




Appendix B – Tree Protection Zone

Approximate Tree Protection Zone size and location.

This image indicates the restriction the tree is imposing on redevelopment of the site.

Tree Management Report - Planning Commission · Coral Tree) located at 202 Tynte Street, North...

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